Reagent
18-Crown-6
Phase transfer catalyst, cation complexation
- Formula
- C₁₂H₂₄O₆
- Detail
- Binds K⁺ strongly (cavity size matches K⁺). 15-Crown-5 for Na⁺.
CatalystC₁₂H₂₄O₆
Reagent
Aluminum Chloride
Lewis acid catalyst
- Formula
- AlCl₃
- Detail
- Activates alkyl halides and acyl halides by making R⁺ or RCO⁺.
- SMILES
Cl[Al](Cl)Cl
CatalystAlCl₃
Reagent
Arylboronic Acids
Coupling partner for Suzuki reactions
- Formula
- ArB(OH)₂
- Detail
- Air-stable, low toxicity. Many commercially available. Pinacol esters also used.
NucleophileArB(OH)₂
Reagent
Borane-THF
Hydroboration reagent
- Formula
- BH₃·THF
- Detail
- Concerted syn addition. No carbocation → no rearrangement.
OtherBH₃·THF
Reagent
Boron Trifluoride
Lewis acid
- Formula
- BF₃ (as BF₃·Et₂O)
- Detail
- Strong Lewis acid. Often used as etherate (BF₃·OEt₂).
CatalystBF₃ (as BF₃·Et₂O)
Reagent
Clemmensen Reduction
Complete reduction of C=O to CH₂
- Formula
- Zn(Hg) + HCl
- Detail
- Acidic conditions. For acid-sensitive compounds, use Wolff-Kishner instead.
ReducingZn(Hg) + HCl
Reagent
DBU
Strong, non-nucleophilic organic base
- Formula
- C₉H₁₆N₂
- Detail
- 1,8-Diazabicyclo[5.4.0]undec-7-ene. Non-nucleophilic amidine base.
BaseC₉H₁₆N₂
Reagent
DCC (Dicyclohexylcarbodiimide)
Coupling reagent for amide/ester formation
- Formula
- C₁₃H₂₂N₂
- Detail
- Activates carboxylic acid. Alternative: EDC (water-soluble).
OtherC₁₃H₂₂N₂
Reagent
DEAD (Diethyl Azodicarboxylate)
Activator for Mitsunobu reaction
- Formula
- EtO₂CN=NCO₂Et
- Detail
- Shock-sensitive! DIAD (diisopropyl analog) is safer alternative.
OtherEtO₂CN=NCO₂Et
Reagent
Dess-Martin Periodinane (DMP)
Very mild oxidation of alcohols
- Formula
- C₁₃H₁₃IO₈
- Detail
- Extremely mild, works at RT. Tolerates many functional groups. Expensive.
OxidizingC₁₃H₁₃IO₈
Reagent
DIBAL-H
Partial reduction of esters to aldehydes
- Formula
- (i-Bu)₂AlH
- Detail
- Temperature critical! At -78°C stops at aldehyde. Warmer or excess gives alcohol.
Reducing(i-Bu)₂AlH
Reagent
Diethyl Tartrate (DET)
Chiral ligand for asymmetric synthesis
- Formula
- C₈H₁₄O₆
- Detail
- D-tartrate: "draws" from right. L-tartrate: "draws" from left (mnemonic).
CatalystC₈H₁₄O₆
Reagent
Dissolving Metal (Na/NH₃)
Reduction of alkynes to trans-alkenes
- Formula
- Na + NH₃(l)
- Detail
- Birch reduction conditions. Liquid ammonia at -33°C. Radical mechanism gives trans product.
ReducingNa + NH₃(l)
Reagent
DMAP (4-Dimethylaminopyridine)
Nucleophilic catalyst for acylations
- Formula
- C₇H₁₀N₂
- Detail
- Super-nucleophilic pyridine. Catalytic amounts (5-10%) are usually sufficient.
- SMILES
CN(C)c1ccncc1
CatalystC₇H₁₀N₂
Reagent
Gilman Reagent (Cuprate)
Conjugate addition and coupling
- Formula
- R₂CuLi
- Detail
- Softer nucleophile than Grignard/organolithium. Prefers conjugate addition.
NucleophileR₂CuLi
Reagent
Grignard Reagent
Carbon nucleophile for C-C bond formation
- Formula
- RMgBr (or RMgCl)
- Detail
- Strictly anhydrous! Made from R-X + Mg in ether. Very basic and nucleophilic.
NucleophileRMgBr (or RMgCl)
Reagent
Grubbs Catalyst
Olefin metathesis catalyst
- Formula
- Cl₂(PCy₃)₂Ru=CHPh
- Detail
- Ru-based, air-stable. 1st gen and 2nd gen available. Nobel Prize 2005.
CatalystCl₂(PCy₃)₂Ru=CHPh
Reagent
H₂/Pd (Catalytic Hydrogenation)
Reduction of C=C, C≡C, and some functional groups
- Formula
- H₂ + Pd/C
- Detail
- Syn addition. Also works with Pt or Ni catalysts. Does NOT reduce isolated C=O.
ReducingH₂ + Pd/C
Reagent
Hydrazine
Reducing agent and nucleophile
- Formula
- N₂H₄
- Detail
- Toxic and potentially explosive! Handle with care.
- SMILES
NN
NucleophileN₂H₄
Reagent
Hydrobromic Acid
Acid for hydrohalogenation
- Formula
- HBr
- Detail
- Markovnikov addition to alkenes. SN1 with tertiary alcohols.
- SMILES
Br
AcidHBr
Reagent
Hydrochloric Acid
Strong acid for protonation and hydrohalogenation
- Formula
- HCl
- Detail
- Weaker acid than HBr, HI for hydrohalogenation.
- SMILES
Cl
AcidHCl
Reagent
Hydroxylamine
Forms oximes from carbonyls
- Formula
- NH₂OH
- Detail
- Usually used as hydrochloride salt (NH₂OH·HCl).
- SMILES
NO
NucleophileNH₂OH
Reagent
IBX (2-Iodoxybenzoic Acid)
Oxidation of alcohols
- Formula
- C₇H₅IO₄
- Detail
- Less soluble than DMP. Used in DMSO. Can be explosive if heated dry.
OxidizingC₇H₅IO₄
Reagent
Iron(III) Bromide
Lewis acid catalyst for halogenation
- Formula
- FeBr₃
- Detail
- Made in situ from Fe + Br₂. Activates Br₂ for EAS.
- SMILES
Br[Fe](Br)Br
CatalystFeBr₃
Reagent
Jones Reagent
Strong oxidation to carboxylic acid
- Formula
- CrO₃/H₂SO₄/H₂O
- Detail
- Aqueous conditions. 1° alcohols go all the way to carboxylic acid.
OxidizingCrO₃/H₂SO₄/H₂O
Reagent
L-Selectride
Stereoselective reduction of ketones
- Formula
- Li[sec-Bu₃BH]
- Detail
- Bulky hydride source. Gives equatorial alcohol from cyclohexanones. K-Selectride is analogous.
ReducingLi[sec-Bu₃BH]
Reagent
LDA (Lithium Diisopropylamide)
Very strong, non-nucleophilic base for enolate formation
- Formula
- LiN(i-Pr)₂
- Detail
- pKa ~36 (conjugate acid). Forms enolates irreversibly. Use at -78°C in THF.
BaseLiN(i-Pr)₂
Reagent
Lindlar Catalyst
Partial reduction of alkynes to cis-alkenes
- Formula
- Pd/CaCO₃/Pb
- Detail
- Poisoned catalyst - lead prevents over-reduction. Syn addition gives cis product.
ReducingPd/CaCO₃/Pb
Reagent
Lithium Aluminum Hydride
Strong reduction of most carbonyl compounds
- Formula
- LiAlH₄
- Detail
- Very reactive! Violently reacts with water. Use anhydrous ether or THF. Quench carefully with water.
- SMILES
[Li+].[AlH4-]
ReducingLiAlH₄
Reagent
Manganese Dioxide
Selective oxidation of allylic/benzylic alcohols
- Formula
- MnO₂
- Detail
- Very selective - only oxidizes activated alcohols. Gentle conditions.
OxidizingMnO₂
Reagent
mCPBA
Epoxidation of alkenes
- Formula
- m-ClC₆H₄CO₃H
- Detail
- meta-Chloroperoxybenzoic acid. Concerted mechanism. Stereospecific.
Oxidizingm-ClC₆H₄CO₃H
Reagent
Mercuric Acetate
Oxymercuration reagent
- Formula
- Hg(OAc)₂
- Detail
- Followed by NaBH₄ to remove Hg. Gives Markovnikov product without carbocation.
OtherHg(OAc)₂
Reagent
Mesyl Chloride
Converts OH to good leaving group (OMs)
- Formula
- MsCl (CH₃SO₂Cl)
- Detail
- Similar to TsCl but smaller. OMs is good leaving group.
Leaving GroupsMsCl (CH₃SO₂Cl)
Reagent
NBS (N-Bromosuccinimide)
Bromination at allylic/benzylic positions
- Formula
- C₄H₄BrNO₂
- Detail
- Provides low concentration of Br₂ for controlled radical bromination.
OtherC₄H₄BrNO₂
Reagent
Nitric Acid
Nitrating agent (with H₂SO₄)
- Formula
- HNO₃
- Detail
- H₂SO₄ protonates HNO₃ to form NO₂⁺ (nitronium ion).
- SMILES
O[N+](=O)[O-]
AcidHNO₃
Reagent
Organolithium
Strong base and carbon nucleophile
- Formula
- RLi (e.g., n-BuLi)
- Detail
- More reactive than Grignard. n-BuLi and t-BuLi most common.
NucleophileRLi (e.g., n-BuLi)
Reagent
Osmium Tetroxide
Syn-dihydroxylation of alkenes
- Formula
- OsO₄
- Detail
- Very toxic! Use catalytically with NMO (N-methylmorpholine N-oxide) as co-oxidant.
OxidizingOsO₄
Reagent
Ozone
Oxidative cleavage of alkenes
- Formula
- O₃
- Detail
- Ozonolysis at -78°C, then workup. Useful for determining alkene structure.
OxidizingO₃
Reagent
PCC (Pyridinium Chlorochromate)
Mild oxidation, stops at aldehyde
- Formula
- C₅H₅NH⁺CrO₃Cl⁻
- Detail
- Anhydrous conditions. Does not over-oxidize to carboxylic acid. CH₂Cl₂ solvent.
OxidizingC₅H₅NH⁺CrO₃Cl⁻
Reagent
Pd(PPh₃)₄ (Tetrakis)
Pd(0) catalyst for cross-coupling
- Formula
- Pd(PPh₃)₄
- Detail
- Air-sensitive (yellow powder). Pre-formed Pd(0). Alternative: Pd(dba)₂ + ligand.
CatalystPd(PPh₃)₄
Reagent
Pd₂(dba)₃
Pd(0) precursor for cross-coupling
- Formula
- Pd₂(dba)₃
- Detail
- dba = dibenzylideneacetone. Add phosphine ligand for activity.
CatalystPd₂(dba)₃
Reagent
PDC (Pyridinium Dichromate)
Mild oxidation of alcohols
- Formula
- C₁₀H₁₂Cr₂N₂O₇
- Detail
- Similar to PCC but less acidic. Good for acid-sensitive substrates.
OxidizingC₁₀H₁₂Cr₂N₂O₇
Reagent
Phosphorus Tribromide
Converts alcohols to alkyl bromides
- Formula
- PBr₃
- Detail
- Works via SN2 mechanism → inversion of stereochemistry.
- SMILES
BrP(Br)Br
OtherPBr₃
Reagent
Potassium Permanganate
Strong oxidation, varies with conditions
- Formula
- KMnO₄
- Detail
- Purple color. Cold/dilute = dihydroxylation. Hot/conc = oxidative cleavage.
OxidizingKMnO₄
Reagent
Potassium tert-Butoxide
Strong, bulky base - favors elimination
- Formula
- KOC(CH₃)₃
- Detail
- Bulky base favors less substituted alkene (Hofmann). Poor nucleophile.
- SMILES
[K+].CC(C)(C)[O-]
BaseKOC(CH₃)₃
Reagent
Pyridine
Mild base and nucleophilic catalyst
- Formula
- C₅H₅N
- Detail
- Aromatic amine. Weaker base than aliphatic amines. Bad smell.
- SMILES
c1ccncc1
BaseC₅H₅N
Reagent
Red-Al (Sodium bis(2-methoxyethoxy)aluminum hydride)
Strong reduction, handles various substrates
- Formula
- NaAlH₂(OCH₂CH₂OMe)₂
- Detail
- Milder than LiAlH₄ but still powerful. Soluble in aromatic solvents.
ReducingNaAlH₂(OCH₂CH₂OMe)₂
Reagent
Silver(I) Oxide
Mild oxidation and halide activation
- Formula
- Ag₂O
- Detail
- Mild oxidizing agent. Creates Ag⁺ as activating species.
OxidizingAg₂O
Reagent
Sodium Azide
Nucleophile for SN2, not basic
- Formula
- NaN₃
- Detail
- Good nucleophile, weak base → favors substitution over elimination.
- SMILES
[Na+].[N-]=[N+]=[N-]
NucleophileNaN₃
Reagent
Sodium Borohydride
Mild reduction of aldehydes and ketones to alcohols
- Formula
- NaBH₄
- Detail
- Does NOT reduce esters, amides, carboxylic acids, or C=C bonds. Works in protic solvents (MeOH, EtOH).
- SMILES
[Na+].[BH4-]
ReducingNaBH₄
Reagent
Sodium Cyanide
Carbon nucleophile for SN2
- Formula
- NaCN
- Detail
- Highly toxic! Nitrile product is versatile synthetic intermediate.
- SMILES
[Na+].[C-]#N
NucleophileNaCN
Reagent
Sodium Cyanoborohydride
Selective reduction of imines
- Formula
- NaBH₃CN
- Detail
- Does NOT reduce aldehydes/ketones at neutral pH. Perfect for reductive amination. Releases HCN - toxic!
ReducingNaBH₃CN
Reagent
Sodium Hydride
Strong base (deprotonation), poor nucleophile
- Formula
- NaH
- Detail
- Not a reducing agent in practice! Just a base. H₂ gas evolved.
- SMILES
[Na+].[H-]
BaseNaH
Reagent
Sodium Hydroxide
Strong base, good nucleophile
- Formula
- NaOH
- Detail
- Strong base and good nucleophile. pKa of water ~16.
- SMILES
[Na+].[OH-]
BaseNaOH
Reagent
Sodium Methoxide
Strong base and nucleophile
- Formula
- NaOCH₃
- Detail
- Use in MeOH solvent. NaOEt in EtOH is analogous. Also acts as nucleophile in SN2.
- SMILES
[Na+].C[O-]
BaseNaOCH₃
Reagent
Sodium Triacetoxyborohydride
Mild, selective reduction
- Formula
- NaBH(OAc)₃
- Detail
- Safer than NaBH₃CN (no HCN). Very selective. Mild conditions.
ReducingNaBH(OAc)₃
Reagent
Sulfuric Acid
Strong acid catalyst
- Formula
- H₂SO₄
- Detail
- Strong acid and dehydrating agent. Use catalytically.
- SMILES
OS(=O)(=O)O
AcidH₂SO₄
Reagent
Swern Oxidation Reagents
Mild oxidation of alcohols to aldehydes/ketones
- Formula
- (COCl)₂ + DMSO + Et₃N
- Detail
- No heavy metals. Very mild. Done at -78°C. Smelly byproduct (dimethyl sulfide).
Oxidizing(COCl)₂ + DMSO + Et₃N
Reagent
TBHP (tert-Butyl Hydroperoxide)
Oxidant for epoxidation and other oxidations
- Formula
- (CH₃)₃COOH
- Detail
- Anhydrous version needed for Sharpless epoxidation. Commercial solutions available.
- SMILES
CC(C)(C)OO
Oxidizing(CH₃)₃COOH
Reagent
Thionyl Chloride
Converts alcohols and acids to chlorides
- Formula
- SOCl₂
- Detail
- Gaseous byproducts (SO₂, HCl) make workup easy. Use pyridine as base.
- SMILES
O=S(Cl)Cl
OtherSOCl₂
Reagent
Tosyl Chloride
Converts OH to good leaving group (OTs)
- Formula
- TsCl (p-CH₃C₆H₄SO₂Cl)
- Detail
- OTs is excellent leaving group, similar to Br⁻. Use pyridine as base.
Leaving GroupsTsCl (p-CH₃C₆H₄SO₂Cl)
Reagent
Triethylamine
Mild base, acid scavenger
- Formula
- Et₃N
- Detail
- Mild base (pKa ~11). Good for neutralizing acid byproducts.
- SMILES
CCN(CC)CC
BaseEt₃N
Reagent
Wittig Reagent (Phosphorus Ylide)
Converts C=O to C=C
- Formula
- Ph₃P=CR₂
- Detail
- Made from Ph₃P + R-X, then strong base. Produces alkene + Ph₃P=O.
NucleophilePh₃P=CR₂
